This invention relates to a novel centerfilled food product and to the process for its production. More particularly, the invention is directed to the production of a tubular centerfilled food product, having a rigid, friable, thermoplastic baked outer shell and a core of edible material surrounded by the shell, by a continuous, straight-through process.
A number of methods have been used heretofore to provide cylindrical centerfilled food products. Such prior methods frequently have involved extruding a mixture of a farinaceous material and water through a restricted orifice into a tubular configuration, under conditions such that the tubular product is puffed or expanded as it emerges from the orifice. The tubular product is cut to length and cooled, and a desired filling is injected into the core of the puffed tubular body. Such methods suffer from the disadvantage that a number of separate steps are involved, each requiring separate handling of the fragile expanded tubular product. Also, because of the high temperatures and pressures to which the mix is subjected in the extruder, the ingredients which may be used in the mix are limited. For example, if the mix has a sugar content of above about 10%, the product tends to scorch or burn during extrusion. As a result, such expanded, extruded products must have a shell which consists essentially of cereal, and accordingly has a high starch content. Since the starch is gelatinized during extrusion, the shell portion of such extruded products is permanently rigid in nature. Moreover, since the puffed tubular body has a relatively high moisture content, usually between about 20%-25%, after extrusion, it must be dried before a desired filling can be injected into the core.
Another procedure which has been disclosed heretofore involves mounting a plurality of cylindrical molds on an endless conveyor, each of the molds having a rod extending horizontally into its interior. A dough is filled into the mold, and the mold carried into an oven for baking. The baked dough tubes are then stripped from the rods and held in a suitable manner to permit filling. This procedure also suffers from the disadvantage that separate shell forming and filling steps are required, each requiring separate handling of the product.
It is readily apparent that a process for making baked centerfilled food products in which the shell is filled simultaneously with its formation would be desirable for it would reduce the number of handling steps involved. Heretofore the only procedure disclosed for such a simultaneous shell forming and filling operation involves a co-extrusion operation in which a shell of cereal dough is extruded around a core of a filling material. However, as noted above, due to the temperatures and pressures to which materials are exposed in the extruder, the ingredients which can be used in such a co-extrusion operation are restricted to thereby limit the type of products produced. In addition, since the puffed tubular body must be dried after extrusion, only filling materials which are not adversely affected by such drying temperatures may be used in such a co-extrusion process.